The normalized expression values (log2) for selected genes as captured by the microarray analysis are plotted for each microarray condition. The profiles of gene expression represent three differentially expressed classes and one control class: A. Surface-induced, LafK-dependent; B, Surface-induced, LafK-independent; C, Surface-repressed, LafK-independent; and D, Representative control genes showing constitutive expression over these conditions. Error bars represent standard error of replicates.